Ultrasonic pattern recognition assemblies, preparation methods thereof and display devices

ABSTRACT

An ultrasonic pattern recognition assembly comprising: a substrate; a receiving member comprising at least one receiving electrode disposed on the substrate; a piezoelectric layer disposed on the substrate and covering the receiving member; a seed member comprising at least one seed block disposed on at least a portion of the piezoelectric layer; an insulating member disposed on the seed member and having at least one exposed portion, the at least one exposed portion exposing a portion of a surface of the seed member; and a transmitting member comprising at least one transmitting electrode disposed on the seed member, the at least one transmitting electrode extending from a surface of the seed member exposed by the exposed portion in a direction away from the substrate. A display device and a method of fabricating an ultrasonic pattern recognition assembly are also disclosed.

The present disclosure claims the benefit of Chinese Patent ApplicationNo. 202010412521.3, entitled “Ultrasonic Pattern Recognition Assembly,Preparation Method Thereof, and Display Device,” filed with the ChinesePatent Office on May 15, 2020, the entire contents of which areincorporated herein by reference.

TECHNICAL FIELD

Embodiments of the present disclosure relate to ultrasonic patternrecognition assemblies, preparation methods thereof, and displaydevices.

BACKGROUND

With the development of science and technology, applications offingerprint recognition technology have become wider and wider. Theultrasonic fingerprint recognition technology has a high recognitionaccuracy and can be used for under-screen fingerprint recognition.

Ultrasonic fingerprint recognition modules generally includetransmitting electrodes, receiving electrodes, and a piezoelectricmaterial layer therebetween. The transmitting electrodes may include aplurality of transmitting electrodes arranged at intervals, and they aretypically prepared by using an electroplating process, during the periodof which the transmitting electrodes are generated in a directionparallel to a substrate while growing in a direction perpendicular tothe substrate. To avoid the situation where a short circuit occursbetween adjacent transmitting electrodes in contact with each other, asufficiently large gap needs to be kept between the two transmittingelectrodes such that the transmitting electrode has a small area incontact with the piezoelectric layer, resulting in a reduction in theenergy of the transmitted ultrasonic wave.

SUMMARY

At least some embodiments of the present disclosure provide anultrasonic pattern recognition assembly comprising: a substrate; Areceiving member comprising at least one receiving electrode disposed onthe substrate; a piezoelectric layer disposed on the substrate andcovering the receiving member; a seed member comprising at least oneseed block disposed on at least a portion of the piezoelectric layer; aninsulating member disposed on the seed member and having at least oneexposed portion, the at least one exposed portion exposing a portion ofa surface of the seed member; and a transmitting member comprising atleast one transmitting electrode disposed on the seed member, the atleast one transmitting electrode extending from a surface of the seedmember exposed by the exposed portion in a direction away from thesubstrate.

In some embodiments of the present disclosure, the at least one seedblock is arranged in an array, for each of the at least one seed block,the at least one exposed portion is arranged in an array, the at leastone exposed portion exposes portions of a surface of the seed block, andone of the at least one transmitting electrode is provided on each ofthe exposed portions of the surface of the seed block.

In some embodiments of the present disclosure, a dimension of a portionof the insulating member located between adjacent two of thetransmitting electrodes satisfies the relationship:

${d > {2*\frac{b}{a}x}};$

where d denotes a dimension of the portion of the insulating memberlocated between the adjacent two of the transmitting electrodes in adirection parallel to the substrate;

$\frac{b}{a}$

denotes a ratio of a growth rate of the transmitting electrode in adirection parallel to the substrate to a growth rate in a directionperpendicular to the substrate; andx denotes a dimension of the transmitting electrode in a directionperpendicular to the substrate.

In some embodiments of the present disclosure, a thickness of theinsulating member ranges from 0.1 μm to 1 μm.

In some embodiments of the present disclosure, a material of theinsulating member comprises at least one of silicon oxide, siliconnitride, and resin.

In some embodiments of the present disclosure, the at least onetransmitting electrode is formed by an electroplating process.

In some embodiments of the present disclosure, a material of the atleast one seed block comprises at least one of molybdenum, copper,titanium, and aluminum.

In some embodiments of the present disclosure, a number of the at leastone receiving electrode is equal to a number of the at least onetransmitting electrode, and the at least one receiving electrode and theat least one transmitting electrode are substantially aligned in adirection perpendicular to the substrate.

In some embodiments of the present disclosure, the at least onereceiving electrode and the at least one transmitting electrode areinterleaved.

In some embodiments of the present disclosure, the substrate is aflexible substrate or a rigid substrate.

In some embodiments of the present disclosure, a dimension of the atleast one transmitting electrode in a direction perpendicular to thesubstrate is 20 μm.

At least some embodiments of the present disclosure provide a displaydevice comprising a display module; and the ultrasonic patternrecognition assembly described as above.

In some embodiments of the present disclosure, a distance of the atleast one transmitting electrode to the display module is less than adistance of the at least one receiving electrode to the display module;or, the distance of the at least one transmitting electrode to thedisplay module is greater than the distance of the at least onereceiving electrode to the display module.

At least some embodiments of the present disclosure provide a method offabricating an ultrasonic pattern recognition assembly, comprising:providing a substrate; forming at least one receiving electrode on thesubstrate; forming a piezoelectric layer on the substrate, thepiezoelectric layer covering the at least one receiving electrode;forming at least one seed block on the piezoelectric layer, the at leastone seed block being arranged in an array; forming an insulating memberon a side of the at least one seed member away from the substrate, theinsulating member being provided with at least one exposed portion, theat least one exposed portion exposing a portion of a surface of the atleast one seed block; and forming at least one transmitting electrode onthe exposed surface of the at least one seed block by using anelectroplating process, the at least one transmitting electrodeextending from the exposed surface of the at least one seed block in adirection away from the substrate.

In some embodiments of the present disclosure, a dimension of a portionof the insulating member located between adjacent two of thetransmitting electrodes satisfies the relationship:

${d > {2*\frac{b}{a}x}};$

where d denotes a dimension of the portion of the insulating memberlocated between the adjacent two of the transmitting electrodes in adirection parallel to the substrate;

$\frac{b}{a}$

denotes a ratio of a growth rate of the transmitting electrode in adirection parallel to the substrate to a growth rate in a directionperpendicular to the substrate; andx denotes a dimension of the transmitting electrode in a directionperpendicular to the substrate.

In some embodiments of the present disclosure, a thickness of theinsulating member ranges from 0.1 μm to 1 μm.

In some embodiments of the present disclosure, a material of theinsulating member comprises at least one of silicon oxide, siliconnitride, and a resin.

In some embodiments of the present disclosure, a material of the atleast one seed block comprises at least one of molybdenum, copper,titanium, and aluminum.

In some embodiments of the present disclosure, a material of the atleast one transmitting electrode comprises at least one of copper,molybdenum, and titanium.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cross-sectional view of an ultrasonic patternrecognition assembly in accordance with an exemplary embodiment of thepresent disclosure;

FIG. 2 is a partial schematic view of a seed member of the ultrasonicpattern recognition assembly shown in FIG. 1;

FIG. 3 is a partial schematic view of one embodiment of a seed memberand an insulating member of the ultrasonic pattern recognition assemblyshown in FIG. 1;

FIG. 4 is a partial schematic view of one embodiment of a seed member,an insulating member, and a transmitting electrode of the ultrasonicpattern recognition assembly shown in FIG. 1;

FIG. 5 is a partial schematic view of another embodiment of a seedmember and an insulating member of the ultrasonic pattern recognitionassembly shown in FIG. 1;

FIG. 6 is a partial schematic view of another embodiment of the seedmember, the insulating member, and the transmitting electrode member ofthe ultrasonic pattern recognition assembly shown in FIG. 1;

FIG. 7 is a partial schematic view of an ultrasonic pattern recognitionassembly according to another exemplary embodiment of the presentdisclosure;

FIG. 8 is a partial schematic view of an ultrasonic pattern recognitionassembly according to yet another exemplary embodiment of the presentdisclosure;

FIG. 9 is a partial schematic view of a seed member of the ultrasonicpattern recognition assembly shown in FIG. 7 or FIG. 8;

FIG. 10 is a partial schematic view of a seed member and an insulatingmember of the ultrasonic pattern recognition assembly shown in FIG. 7 orFIG. 8;

FIG. 11 is a partial schematic view of a seed member, an insulatingmember, and a transmitting electrode member of the ultrasonic patternrecognition assembly shown in FIG. 7 or FIG. 8;

FIG. 12 is a partial schematic view of an ultrasonic pattern recognitionassembly according to yet another exemplary embodiment of the presentdisclosure;

FIG. 13 is a flowchart of a method of manufacturing an ultrasonicpattern recognition assembly according to an exemplary embodiment of thepresent disclosure;

FIG. 14 is a schematic structural view of a display device according toan exemplary embodiment of the present disclosure; and

FIG. 15 is a schematic structural view of a display device providedaccording to another exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to exemplary embodiments, examplesof which are illustrated in the accompanying drawings. When thefollowing description refers to the drawings, the same numbers indifferent drawings represent the same or similar elements unlessotherwise indicated. The embodiments described in the followingexemplary embodiments do not represent all embodiments consistent withthe present disclosure. Rather, they are merely examples of apparatusand methods consistent with some aspects of the disclosure, as detailedin the following claims.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used in this disclosure and the appended claims, the singular forms“a”, “an” and “the” are intended to include the plural forms as well,unless the context clearly indicates otherwise. It will also beunderstood that the term “and/or” as used herein refers to andencompasses any and all possible combinations of one or more of theassociated listed items.

It will be understood that, although the terms first, second, third,etc. may be used herein to describe various information, they should notbe limited by these terms. These terms are only used to distinguish onetype of information from each other. For example, first informationcould also be termed as second information, and, similarly, secondinformation could also be termed as first information, without departingfrom the scope of the present disclosure. The word “if” as used hereinmay be construed as “at” or “when” or “in response to determining”depending on the context.

An ultrasonic pattern recognition assembly includes a transmittingelectrode member, a receiving electrode member, and a piezoelectriclayer therebetween, in which the transmitting electrode member isconfigured to have a relatively large thickness so that the ultrasonicpattern recognition assembly may have a certain resonant frequency. Whena metal electrode has a relatively large thickness, a time period foretching is relatively long and efficiency thereof is relatively low ifthe etching is performed by using a photolithography process. Intechnologies known to the inventors, transmitting electrodes aregenerally prepared by using an electroplating process. When thetransmitting electrodes are formed by using the electroplating process,the transmitting electrodes are grown simultaneously both in a directionparallel to the substrate and in a direction perpendicular to thesubstrate. A relatively large gap is reserved between the neighboringtransmitting electrodes at a side near the piezoelectric layer to avoidthe neighboring transmitting electrodes from contacting, resulting in asmall area of the transmitting electrodes near the surface of thepiezoelectric layer, thereby resulting in a reduced driving ability ofthe transmitting electrodes to the piezoelectric layer.

An ultrasonic pattern recognition assembly and a manufacturing methodthereof and a display device according to the embodiments of the presentdisclosure will be described in detail below with reference to theaccompanying drawings. The features in the embodiments described belowmay be supplemented or combined with each other in case of no conflict.

At least one embodiment of the present disclosure provides an ultrasonicpattern recognition assembly. The ultrasonic pattern recognitionassembly includes: a substrate; a receiving member including at leastone receiving electrode disposed on the substrate; a piezoelectric layerdisposed on the substrate and covering the receiving member; a seedmember including at least one seed block disposed on at least a portionof the piezoelectric layer; an insulating member disposed on the seedmember and having at least one exposed portion that exposes a portion ofa surface of the seed member; and a transmitting member including atleast one transmitting electrode disposed on the seed member, where theat least one transmitting electrode extends from a surface of the seedmember exposed by the at least one exposed portion in a direction awayfrom the substrate.

Referring to FIGS. 1 to 12, the ultrasonic pattern recognition assembly100 includes a substrate 10, a receiving member, a piezoelectric layer30, a seed member 40, an insulating member 50, and a transmittingmember.

The receiving member, the piezoelectric layer 30, the seed member 40,the insulating member 50 and the transmitting member are located on thesubstrate 10. The receiving member includes at least one receivingelectrode 20 disposed on the substrate. The piezoelectric layer 30 isdisposed on the substrate 10 and covers the receiving member. The seedmember 40 includes at least one seed block disposed on at least aportion of the piezoelectric layer 30. The insulating member 50 isdisposed on the seed member 40 and has at least one exposed portion 51exposing a portion of the surface of the seed member 40. Thetransmitting member includes at least one transmitting electrode 60disposed on the seed member 40, the at least one transmitting electrode60 extending from an exposed surface of the seed member 40 in adirection away from the seed member 40.

In the ultrasonic pattern recognition assembly 100 according toembodiments of the present disclosure, the at least one exposed portionof the insulating member 50 exposes a portion of the surface of the seedmember 40, and the at least one transmitting electrode 60 extends fromthe exposed surface of the seed member 40 in a direction away from thesubstrate 10, such that an area of a surface of each seed member 40parallel to the piezoelectric layer 30 is larger than an area of acontact surface of the at least one transmitting electrode 60 with theseed member 40. Meanwhile, in the ultrasonic pattern recognitionassembly 100 according to embodiments of the present disclosure, the atleast one transmitting electrode 60 can drive the piezoelectric layer 30through the seed member 40, and thus the driving ability of the at leastone transmitting electrode 60 to the piezoelectric layer 30 can beprevented from being decreased with ensuring adjacent transmittingelectrodes being not in contact, and the accuracy of pattern recognitioncan be improved.

In operation of the ultrasonic pattern recognition assembly, a drivingvoltage is applied to the at least one transmitting electrode, thereceiving member is grounded, and the piezoelectric layer 30 generatesultrasonic waves under excitation of the driving voltage. In embodimentsof the present disclosure, the driving voltage can be applied to the atleast one transmitting electrode through the seed member 40. Theultrasonic wave generated by the piezoelectric layer 30 propagates to apattern to be identified and is reflected by the pattern. The reflectedultrasonic wave propagates to the piezoelectric layer 30 which convertsthe reflected ultrasonic wave into electrical signals. The receivingmember outputs the electrical signals to a chip, and the chip generatesa pattern image according to the received electrical signals andperforms pattern recognition. The pattern includes fingerprint, palmprint, toe print, and the like.

The ultrasonic pattern recognition assembly may include a functionalregion and a bonding region, where the substrate 10, the receivingmember, the piezoelectric layer 30, the seed member 40, the insulatingmember 50 and the transmitting member may be located in the functionalregion, and the bonding region may be provided with traces each havingone end for electrically connecting with the seed member and thetransmitting member and another end for connecting to the chip.

In an embodiment of the present disclosure, the substrate 10 may be aflexible substrate or a rigid substrate. The flexible substrate may bemade of one or more of PET (polyethylene terephthalate), PI (polyimide)and PC (polycarbonate). The material of the rigid substrate may beglass, metal, or the like.

In one embodiment of the present disclosure, the receiving member mayinclude a plurality of receiving electrodes 20 arranged at intervals. Anorthographic projection of each receiving electrode 20 on the substrate10 at least partially overlaps with an orthographic projection of theseed member 40 on the substrate 10, so that an electric field may begenerated, and thus ultrasonic waves may be generated by thepiezoelectric layer, when a voltage is applied to the seed member andthe receiving electrodes.

The ultrasonic pattern recognition assembly may further include abonding region, which is provided with a plurality of traces, located atan edge. Each of the receiving electrodes 20 is connected to the chip bya respective trace in the bonding region. The chip may apply a voltageto the receiving electrodes 20 or may receive electrical signals outputby the receiving electrodes 20 via the traces. A number of the receivingelectrodes 20 may be identical to that of the transmitting electrodes60, and the plurality of receiving electrodes 20 respectively receiveelectrical signals converted from the ultrasound waves reflected bydifferent positions of the pattern to be identified and output theelectrical signals.

In an embodiment of the present disclosure, an orthographic projectionof the piezoelectric layer 30 on the substrate 10 covers the entire areaof the substrate 10. The piezoelectric layer is made of a piezoelectricmaterial and may not only convert ultrasonic waves into electricalsignals, but also convert electrical signals into ultrasonic waves underan electric field.

In an embodiment of the present disclosure, the material of the seedmember 40 may be a metal with relatively good conductivity, such asmolybdenum, copper, titanium, aluminum, or the like.

In an embodiment of the present disclosure, a thickness of theinsulating member 50 ranges from 0.1 μm to 1 μm. As such, it can beavoided that the process cannot be achieved easily due to a too smallthickness of the insulating member 50, and that the growth of the atleast one transmitting electrode 60 may be affected due to a too largethickness of the insulating member. The thickness of the insulatingmember 50 may be, for example, 0.1 μm, 0.3 μm, 0.5 μm, 0.8 μm, 1 μm, orthe like.

In an embodiment of the present disclosure, the material of theinsulating member 50 includes at least one of silicon oxide, siliconnitride, and resin. The Young's modulus of the materials such as siliconoxide, silicon nitride and resin is relatively large, so that the amountof attenuation of the ultrasound waves reflected by the pattern to berecognized is small when passing through the insulating member 50 madeof these materials, the energy of the reflected ultrasound wavesreceived by the piezoelectric layer 30 is relatively high, and thesignal strength of the electrical signal converted is strong, and theaccuracy of pattern recognition is improved.

In an embodiment of the present disclosure, the transmitting electrode60 may be made of a material with relatively good conductivity, such ascopper, molybdenum, titanium, or the like.

In an embodiment of the present disclosure, the at least onetransmitting electrode 60 is formed by using an electroplating process.The at least one transmitting electrode 60 is grown simultaneously in adirection parallel to the substrate and in a direction perpendicular tothe substrate during the process of growth, and the resultedtransmitting electrode 60 has a cross-section substantially in a shapeof an inverted trapezoid in a direction perpendicular to the substrate.A size of a portion of the insulating member located between adjacenttwo of the transmitting electrodes satisfies the following relationship:

${d > {2*\frac{b}{a}x}};$

where d denotes a dimension of the portion of the insulating memberlocated between the adjacent two of the transmitting electrodes in adirection parallel to the substrate;

$\frac{b}{a}$

denotes a ratio of a growth rate of the transmitting electrode in adirection parallel to the substrate to a growth rate in a directionperpendicular to the substrate; andx denotes a dimension of the transmitting electrode in a directionperpendicular to the substrate.

As such, when the size of the transmitting electrode 60 in the directionperpendicular to the substrate is x, the growth size of the transmittingelectrode 60 in the direction parallel to the substrate is (b/a)*x, dueto the interval

$d > {2*\frac{b}{a}x}$

of the adjacent transmitting electrodes on the seed member, contact ofsides of the adjacent two transmitting electrodes 60 away from thepiezoelectric layer 30 can be avoid, thereby avoiding signal crosstalkformed after the ultrasound waves reflected by the pattern pass throughthe transmitting electrodes 60.

In an exemplary embodiment of the present disclosure, the size of thetransmitting electrode in the direction perpendicular to the substrateis 20 μm, the growth rate of the transmitting electrode in the directionparallel to the substrate to the growth rate in the directionperpendicular to the substrate

$\frac{b}{a}$

is equal to 3:4, and the interval d of adjacent two transmittingelectrodes 60 on the seed member is >30 μm (2*(3:4)*20). When thetransmitting electrode is grown to 20 μm in the direction perpendicularto the substrate, the adjacent two transmitting electrodes 60 do notcontact, so that the ultrasound waves reflected by the pattern do notcrosstalk.

In some embodiments of the present disclosure, referring to FIG. 12,when the at least one transmitting electrode 60 is formed by anelectroplating process, the resulted transmitting electrode 60 may alsobe substantially mushroom-like. The transmitting electrode 60 includes afirst portion 61 located in the exposed portion and a second portion 62which is disposed on the first portion 61 and on the insulating member50. A surface of the second portion 62 near the piezoelectric layer 30abuts the surface of the insulating member 50. As such, the insulatingmember 50 is arranged such that it can be avoided that air may bepresent between the second portion 62 and the piezoelectric layer 30,resulting in a great magnitude of attenuation as the ultrasonic wavepasses.

In an embodiment of the present disclosure, referring to FIGS. 1 to 6,the seed member 40 includes a plurality of seed blocks 41 arranged atintervals, the insulating member 50 covers adjacent ones of the seedblocks 41 and is provided with at least one exposed portion 51 to exposeat least a portion of a surface of the seed blocks 41, and at least onetransmitting electrode 60 is formed on each of the seed blocks 41. Eachof the seed blocks 41 is connected to a respective trace of the bondingregion 70, which is connected to a respective control port of the chip,so that the chip can control the driving voltage applied to each of theseed blocks 41. When a voltage is applied to the seed block 41, an areaof the piezoelectric layer 30 corresponding to the seed block 41generates ultrasonic waves. The time at which the driving voltage isapplied to each of the seed blocks 41 is different, so that the time atwhich the ultrasonic waves are generated in a region of thepiezoelectric layer 30 corresponding to a respective seed block 41 isdifferent. By controlling the time at which the driving voltage isapplied to each of the seed blocks 41, that the ultrasound wavesgenerated by different regions of the piezoelectric layer 30 aresuperimposed at a position of the pattern nay be achieved so that anenergy of the ultrasound wave at the position is high, the energy of theultrasound wave reflected by the pattern at the position is also high,and thus the signal strength of the electrical signal generated by thepiezoelectric layer 30 is high, and the accuracy of the fingerprintrecognition can be improved.

In the embodiment shown in FIGS. 3 and 4, the seed member includes aplurality of seed blocks 41, each having a strip shape and being spacedparallel to each other at intervals. The insulating member 50 includes aplurality of strip-shaped insulating portions, and a gap betweenadjacent two strip-shaped insulating portions forms an exposed portionof the insulating member 50, exposing a portion of the surface of eachseed block 41. Each of the strip-shaped insulating members covers a gapbetween two adjacent seed blocks 41, and portions of the two seed blocks41 adjacent to the gap. Each of the seed blocks 41 is provided with arespective transmitting electrode 60 thereon, which extends in the samedirection as the corresponding seed block 41. For more clearlyillustrating the structure of the seed block 41, the insulating member50 and the transmitting electrode 60, a portion of the insulating member50 and a portion of the transmitting electrode 60 in the region A ofFIG. 4 is not shown, and in fact, the structure of the region A is thesame as the structure of other regions.

In the embodiment shown in FIGS. 5 and 6, a plurality of strip-shapedseed blocks 41 are provided on the piezoelectric layer, and a pluralityof transmitting electrodes 60 are provided on each of the seed blocks41. The insulating member 50 covers the entire substrate and is providedwith a plurality of vias arranged at intervals as a plurality of exposedportions 51, each exposing a portion of the surface of the seed block41.

In an embodiment of the present disclosure, referring to FIGS. 5 and 6,a plurality of seed blocks 41 are arranged at intervals in parallel in afirst direction, each of the plurality of seed blocks 41 having aplurality of transmitting electrodes 60 disposed thereon, and aplurality of transmitting electrodes 60 correspondingly arranged on eachof the plurality of seed blocks 41 are arranged at intervals in a seconddirection, the first direction intersecting the second direction. Inthis way, when the ultrasound waves generated by the region of thepiezoelectric layer 30 corresponding to the seed block 41 are reflectedby the different locations of the pattern and then propagate toward thepiezoelectric layer 30, the ultrasound waves reflected by the differentlocations propagate through the different transmitting electrodes 60provided on the seed block 41. Since the adjacent two transmittingelectrodes 60 are provided with an insulating material having anacoustic impedance different from the acoustic impedance of thetransmitting electrodes 60, it is possible to prevent the reflectedultrasonic waves from transverse wave propagating to the adjacenttransmitting electrodes as they pass through the transmitting electrodes60, to avoid crosstalk of the ultrasonic waves reflected by thedifferent locations of the pattern which affects the accuracy of patternrecognition. That is, by arranging the plurality of seed blocks 41 to beparallel in a first direction and the plurality of transmittingelectrodes 60 arranged at intervals on each of the seeds blocks 41 in asecond direction, the ultrasound waves generated by different regions ofthe piezoelectric layer 30 can be both superimposed in the firstdirection, and the ultrasound waves reflected by different locations ofthe pattern can be avoided from crosstalk upon propagating, and theaccuracy of the pattern recognition can be further improved. To moreclearly illustrate the structure of the seed members 40, the insulatingmembers 50 and the transmitting electrodes 60, both a portion of theinsulating member 50 and a portion of the transmitting electrode 60 arenot shown in the region B of FIG. 6, and in fact, the structure of theregion B is the same as the structure of the other regions.

In an embodiment of the present disclosure, the first direction and thesecond direction may be perpendicular to each other. The first directionmay be a row direction and the second direction may be a columndirection. Alternatively, the first direction may be a column directionand the second direction may be a row direction. In some embodiments ofthe present disclosure, the angle between the first direction and thesecond direction may not be equal to 90°.

In an embodiment of the present disclosure, a plurality of seed blocks41 are disposed on the piezoelectric layer, and the plurality of seedblocks 41 are arranged in an array. On each of the plurality of seedblocks 41, one transmitting electrode may be provided, or a plurality oftransmitting electrodes may be provided. In a case where a plurality oftransmitting electrodes are provided, the plurality of transmittingelectrodes are arranged in an array on the seed block.

In another embodiment of the present disclosure, referring to FIGS. 7 to11, orthographic projection of the seed member 40 on the substrate 10covers the entire area of the substrate 10, and the insulating member 50includes a plurality of vias arranged at intervals as a plurality ofexposed portions 51. The seed member 40 is connected to the chip by atrace of the bonding region 70. As such, when the driving voltage isapplied to the seed member 40 and the receiving electrode 20, respectiveregions of the piezoelectric layer 30 generate ultrasonic waves at thesame time, the generated ultrasonic waves are reflected after reachingdifferent positions of the pattern to be identified, and the reflectedultrasonic waves are converted to electrical signals after reaching thepiezoelectric layer 30, so that the chip can acquire the patterninformation at different positions of the pattern to be identified,which can improve the efficiency of pattern recognition, and help toreduce power consumption.

As shown in FIGS. 10 and 11, the plurality of exposed portions 51 of theinsulating member 50 are a plurality of vias arranged at intervals. Tomore clearly illustrate the structure of the seed member 40, theinsulating member 50 and the transmitting electrode 60, both a portionof the insulating member 50 and a portion of the transmitting electrode60 are not shown in the region C of FIG. 11, and in fact, the structureof the region C is the same as the structure of the other regions.

In an embodiment of the present disclosure, the plurality oftransmitting electrodes 60 and the plurality of receiving electrodes 20may have a one-to-one correspondence. In some embodiments of the presentdisclosure, as shown in FIG. 7, the transmitting electrode 60 issubstantially aligned with the corresponding receiving electrode 20 in adirection perpendicular to the substrate, and an orthographic projectionof the transmitting electrode 60 on the substrate 10 is substantiallycoincident with an orthographic projection of the receiving electrode 20on the substrate 10. In some other embodiments of the presentdisclosure, as shown in FIG. 8, the transmitting electrode 60 is notaligned with the corresponding receiving electrode 20 in a directionperpendicular to the substrate, the orthographic projection of thetransmitting electrode 60 on the substrate 10 is barely coincident withor less coincident with the orthographic projection of the receivingelectrode 20 on the substrate 10, and the orthographic projection of thereceiving electrode 20 on the substrate 10 is mostly coincident with theorthographic projection of the insulating member 50 on the substrate 10.

At least one embodiment of the present disclosure also provides a methodof fabricating an ultrasonic pattern recognition assembly. Referring toFIG. 13, the fabricating method includes the following steps S210 toS260.

In step S210, a substrate is provided.

In an embodiment of the present disclosure, the substrate may be aflexible substrate or a rigid substrate. The material of the flexiblesubstrate may be PET, PI or PC. The material of the rigid substrate maybe glass, metal, or the like.

In step S220, at least one receiving electrode is formed on thesubstrate.

In an embodiment of the present disclosure, a conductive layer is formedon the substrate by a sputtering process, and then the conductive layeris patterned to form a plurality of receiving electrodes arranged atintervals. The plurality of receiving electrodes arranged at intervalsform a receiving member.

The ultrasonic pattern recognition assembly may include a functionalregion and a bonding region. The receiving electrodes are disposed inthe functional region, traces are disposed in the bonding region. Eachof the receiving electrodes is connected to a different trace in thebonding region, and one end of the trace is connected to the chip, sothat the chip can apply a voltage to the receiving electrode.

In step S230, a piezoelectric layer is formed on the substrate, thepiezoelectric layer covering the at least one receiving electrode.

The piezoelectric layer is formed in the functional region. In someembodiments of the present disclosure, a projection of the piezoelectriclayer on the substrate covers the entire area of the substrate. In someembodiments of the present disclosure, the projection of thepiezoelectric layer on the substrate covers a portion of an area of thesubstrate.

In step S240, at least one seed block is formed on the piezoelectriclayer, the at least one seed block being arranged in an array.

In some embodiments of the present disclosure, a conductive layer may beformed on a side of the piezoelectric layer away from the substrate by asputtering process. In some embodiments of the present disclosure, theconductive layer is patterned after the conductive layer is formed toobtain at least one seed block. In some embodiments of the presentdisclosure, the at least one seed block is arranged in rows. In someembodiments of the present disclosure, the at least one seed block isarranged in columns. In some other embodiments of the presentdisclosure, the at least one seed block is arranged in an array. In someembodiments of the present disclosure, after the conductive layer isformed, the conductive layer may not be patterned, and the entireconductive layer may be used as a seed block.

When the seed member includes a plurality of seed blocks, each of theseed blocks is connected to the chip by a different trace in the bondingregion, respectively. When the seed member includes one seed block, theseed member is connected to the chip through a trace of the bondingregion.

In some embodiments of the present disclosure, a conductive layer may beformed on a side of the piezoelectric layer away from the substrate by asputtering process, and then a patterning process is performed on theconductive layer to form a plurality of seed blocks in strips andparallel to each other.

In step S250, an insulating member is formed on a side of the seedmember away from the substrate, the insulating member being providedwith at least one exposed portion, the at least one exposed portionexposing a portion of a surface of the at least one seed block inone-to-one correspondence.

In an embodiment of the present disclosure, an insulating film layer isfirst formed on the seed member, and an orthographic projection of theinsulating film layer on the substrate covers the entire area of thesubstrate. The insulating film layer is then patterned to form aplurality of exposed portions on the insulating film layer, therebyforming an insulating member.

In step S240, when the at least one seed block is arranged in rows orcolumns, after the insulating film layer is formed, the insulating filmlayer is patterned to form a plurality of parallel stripe-shapedinsulating structures, and a gap is formed between two adjacentstripe-shaped insulating structures, thereby forming a bare portion.Each of the stripe-shaped insulating structures covers a gap between twoadjacent seed blocks, and an edge portion of the seed block adjacent tothe gap. As such, one transmitting electrode may be formed on each ofthe seed blocks in subsequent processes. In some embodiments of thepresent disclosure, in a case where a plurality of seed blocks in astrip shape and parallel to each other are formed, the plurality ofexposed portions of the insulating member are a plurality of vias, and aplurality of vias are correspondingly provided on each of the seedblocks.

In another embodiment of the present disclosure, the seed member coversthe entire substrate, and the plurality of exposed portions in theinsulating member are a plurality of vias arranged at intervals.

In step S260, at least one transmitting electrode is formed on theexposed surface of the at least one seed block by using anelectroplating process, the at least one transmitting electrodeextending from the surface of the at least one seed block exposed by theexposed portion in a direction away from the substrate.

In an embodiment of the present disclosure, a number of the at least onetransmitting electrode is the same as a number of the at least onereceiving electrode, and there is a one-to-one correspondence betweenthe at least one transmitting electrode and the at least one receivingelectrode. Each of the at least one transmitting electrode issubstantially aligned with a corresponding receiving electrode in adirection perpendicular to the substrate, and an orthographic projectionof the transmitting electrode on the substrate is substantiallycoincident with an orthographic projection of the correspondingreceiving electrode on the substrate. Alternatively, the transmittingelectrode and the receiving electrode are not aligned in a directionperpendicular to the substrate, the orthographic projection of thetransmitting electrode on the substrate is barely coincident or lesscoincident with the orthographic projection of the receiving electrodeon the substrate, and the orthographic projection of the transmittingelectrode on the substrate is mostly coincident with the orthographicprojection of the insulating member on the substrate.

In an embodiment of the present disclosure, a size of a portion of theinsulating member located between adjacent two of the transmittingelectrodes satisfies the relationship:

${d > {2*\frac{b}{a}x}};$

where d denotes a dimension of the portion of the insulating memberlocated between the adjacent two of the transmitting electrodes in adirection parallel to the substrate;

$\frac{b}{a}$

denotes a ratio of a growth rate of the transmitting electrode in adirection parallel to the substrate to a growth rate in a directionperpendicular to the substrate; andx denotes a dimension of the transmitting electrode in a directionperpendicular to the substrate.

For the method embodiments, since they substantially correspond to theproduct embodiments, a description of the relevant details andadvantages will be made with reference to portions of the description ofthe product embodiments and will not be repeated herein.

In a method of fabricating an ultrasonic pattern recognition assemblyaccording to an embodiment of the present disclosure, a plurality ofexposed portions of the insulating member expose portions of a surfaceof the seed block, and the transmitting electrode extends from theexposed surface of the seed block in a direction away from thesubstrate, thus the total area of the seed member is larger than thetotal area of the contact area of the respective transmitting electrodeswith the seed block. Since the transmitting electrode drives thepiezoelectric layer through the seed block, the ultrasonic patternrecognition assembly according to an embodiment of the presentdisclosure can improve the accuracy of pattern recognition by avoiding areduction in the driving ability of the transmitting electrode to thepiezoelectric layer while ensuring that adjacent transmitting electrodesare not in contact.

At least one embodiment of the present disclosure also provides adisplay device. Referring to FIG. 14 or FIG. 15, the display deviceincludes a display module 200 and any of the ultrasonic patternrecognition assemblies 100 described above.

In an embodiment of the present disclosure, the distance of thetransmitting electrode to the display module 200 is less than thedistance of the receiving electrode to the display module 200;alternatively, the distance of the transmitting electrode to the displaymodule 200 is greater than the distance of the receiving electrode tothe display module 200.

In the display device shown in FIG. 14, the distance from thetransmitting electrode of the ultrasonic pattern recognition assembly100 to the display module 200 is smaller than the distance from thereceiving electrode to the display module 200, and the display module200 is in direct contact with the transmitting electrode 60. Duringultrasonic recognition of the ultrasonic pattern recognition assembly,the pattern to be identified is disposed on a side of the display moduleaway from the ultrasonic pattern recognition assembly. The ultrasoundwaves reflected by the pattern propagate through the transmittingelectrode 60 during transmission to the piezoelectric layer 30, and thetransmitting electrode 60 can avoid crosstalk of the ultrasound wavesand help to improve the accuracy of the pattern recognition.

In the display device shown in FIG. 15, the distance from thetransmitting electrode of the ultrasonic pattern recognition assembly100 to the display module 200 is greater than the distance from thereceiving electrode to the display module 200, and the display module200 is in direct contact with the substrate 10.

The display device according to the embodiments of the presentdisclosure may be, for example, a mobile phone, a tablet computer, atelevision, a laptop computer, or any device with a display function.

It is noted that in the drawings, the dimensions of layers and regionsmay be exaggerated for clarity of illustration. It will also beunderstood that when an element or layer is referred to as being “on”another element or layer, it can be directly on the other element orintervening layers may be present. In addition, it will be understoodthat when an element or layer is referred to as being “under” anotherelement or layer, it can be directly under the other element or morethan one intervening layer or element may be present. In addition, itwill also be understood that when a layer or element is referred to asbeing “between” two layers or elements, it can be the only layer betweenthe two layers or elements, or more than one intervening layer orelement may also be present. Like reference numerals refer to likeelements throughout.

Other embodiments of the present disclosure will be apparent to thoseskilled in the art from consideration of the specification and practiceof the disclosure disclosed herein. This disclosure is intended to coverany variations, uses, or adaptations of the present disclosure whichfollow the general principles of the present disclosure, and whichinclude common general knowledge or customary practice in the art towhich the present disclosure is not disclosed. It is intended that thespecification and embodiments can be considered as exemplary only, witha true scope and spirit of the present disclosure being indicated by thefollowing claims.

It is to be understood that the present disclosure is not limited to theprecise construction described above and illustrated in the drawings,and that various modifications and changes may be made without departingfrom the scope thereof. The scope of the present disclosure is limitedonly by the following claims.

1. An ultrasonic pattern recognition assembly, comprising: a substrate;a receiving member comprising at least one receiving electrode disposedon the substrate; a piezoelectric layer disposed on the substrate andcovering the receiving member; a seed member comprising at least oneseed block disposed on at least a portion of the piezoelectric layer; aninsulating member disposed on the seed member and having at least oneexposed portion, the at least one exposed portion exposing a portion ofa surface of the seed member; and a transmitting member comprising atleast one transmitting electrode disposed on the seed member, the atleast one transmitting electrode extending from a surface of the seedmember exposed by the exposed portion in a direction away from thesubstrate.
 2. The ultrasonic pattern recognition assembly according toclaim 1, wherein the at least one seed block is arranged in an array,for each of the at least one seed block, the at least one exposedportion is arranged in an array, the at least one exposed portionexposes portions of a surface of the seed block, and one of the at leastone transmitting electrode is provided on each of the exposed portionsof the surface of the seed block.
 3. The ultrasonic pattern recognitionassembly according to claim 1, wherein a dimension of a portion of theinsulating member located between adjacent two of the transmittingelectrodes satisfies the relationship: ${d > {2*\frac{b}{a}x}};$ where ddenotes a dimension of the portion of the insulating member locatedbetween the adjacent two of the transmitting electrodes in a directionparallel to the substrate; $\frac{b}{a}$ denotes a ratio of a growthrate of the transmitting electrode in a direction parallel to thesubstrate to a growth rate in a direction perpendicular to thesubstrate; and x denotes a dimension of the transmitting electrode in adirection perpendicular to the substrate.
 4. The ultrasonic patternrecognition assembly according to claim 1, wherein a thickness of theinsulating member ranges from 0.1 μm to 1 μm.
 5. The ultrasonic patternrecognition assembly according to claim 1, wherein a material of theinsulating member comprises at least one of silicon oxide, siliconnitride, and resin.
 6. The ultrasonic pattern recognition assemblyaccording to claim 1, wherein the at least one transmitting electrode isformed by an electroplating process.
 7. The ultrasonic patternrecognition assembly according to claim 1, wherein a material of the atleast one seed block comprises at least one of molybdenum, copper,titanium, and aluminum.
 8. The ultrasonic pattern recognition assemblyaccording to claim 1, wherein a number of the at least one receivingelectrode is equal to a number of the at least one transmittingelectrode, and the at least one receiving electrode and the at least onetransmitting electrode are substantially aligned in a directionperpendicular to the substrate.
 9. The ultrasonic pattern recognitionassembly according to claim 1, wherein the at least one receivingelectrode and the at least one transmitting electrode are interleaved.10. The ultrasonic pattern recognition assembly according to claim 1,wherein the substrate is a flexible substrate or a rigid substrate. 11.The ultrasonic pattern recognition assembly according to claim 1,wherein a material of the at least one transmitting electrode comprisesat least one of copper, molybdenum, and titanium.
 12. The ultrasonicpattern recognition assembly according to claim 1, wherein a dimensionof the at least one transmitting electrode in a direction perpendicularto the substrate is 20 μm.
 13. A display device comprising: a displaymodule; and the ultrasonic pattern recognition assembly according toclaim
 1. 14. The display device according to claim 13, wherein adistance of the at least one transmitting electrode to the displaymodule is less than a distance of the at least one receiving electrodeto the display module; or, the distance of the at least one transmittingelectrode to the display module is greater than the distance of the atleast one receiving electrode to the display module.
 15. A method offabricating an ultrasonic pattern recognition assembly, comprising:providing a substrate; forming at least one receiving electrode on thesubstrate; forming a piezoelectric layer on the substrate, thepiezoelectric layer covering the at least one receiving electrode;forming at least one seed block on the piezoelectric layer, the at leastone seed block being arranged in an array; forming an insulating memberon a side of the at least one seed member away from the substrate, theinsulating member being provided with at least one exposed portion, theat least one exposed portion exposing a portion of a surface of the atleast one seed block; and forming at least one transmitting electrode onthe exposed surface of the at least one seed block by using anelectroplating process, the at least one transmitting electrodeextending from the exposed surface of the at least one seed block in adirection away from the substrate.
 16. The method according to claim 15,wherein a dimension of a portion of the insulating member locatedbetween adjacent two of the transmitting electrodes satisfies therelationship: ${d > {2*\frac{b}{a}x}};$ where d denotes a dimension ofthe portion of the insulating member located between the adjacent two ofthe transmitting electrodes in a direction parallel to the substrate;$\frac{b}{a}$ denotes a ratio of a growth rate of the transmittingelectrode in a direction parallel to the substrate to a growth rate in adirection perpendicular to the substrate; and x denotes a dimension ofthe transmitting electrode in a direction perpendicular to thesubstrate.
 17. The method according to claim 15 or 16, wherein athickness of the insulating member ranges from 0.1 μm to 1 μm.
 18. Themethod according to claim 15, wherein a material of the insulatingmember comprises at least one of silicon oxide, silicon nitride, and aresin.
 19. The method according to claim 15, wherein a material of theat least one seed block comprises at least one of molybdenum, copper,titanium, and aluminum.
 20. The method according to claim 15, wherein amaterial of the at least one transmitting electrode comprises at leastone of copper, molybdenum, and titanium.